Hair building solids may take different forms. However, typically they are powders and/or fibres. The fibres are relatively narrow (typically less than 200 nm in diameter) and short (typically less than 0.7 mm in length). They typically comprise keratin, rayon or nylon. The solids may be coloured to match a user's hair. The solids are applied to the scalp and/or the hairs of the user typically in an area where the user has suffered hair loss. The solids adhere to the hairs and/or scalp and in the case of the former help to thicken the hairs appearance, and in the case of the latter to camouflage the skin.
The adherence of the solids to the scalp/hairs is typically enabled by means of electrostatic charge, although other means such as adhesives (for example hair spray) may be used. The solids are typically electrostatically non-conductive and thus an electrostatic charge may be built up on their surface. This build up may be due to contact with other surfaces, such as other solids, or the container in which the solids are stored. The built-up charge may last a relatively long time on the surface of the solids until such time as they are discharged to a neutral or oppositely charged surface.
In a known embodiment, the solids are provided in a dispenser which includes a sieve at one end in a similar style to a pepper pot. As the solids are dispensed from the dispenser, by either being shaken out, and/or by gravity, the electrostatic charge on the surface of at least some of the solids is affected such that they naturally adhere to the hair and/or scalp of the user. The charge is affected by the movement of the solids across and past the material making up the sieve, and collision with each other. The charge may be affected by the number, size, shape, concavity, angle, spacing, and pattern of the holes in the sieve, and the dimensions of the sieve itself. The material comprising or at least partially coating the sieve and/or the solids may also affect the charging of the solids. The sieve is a single piece of material that varies in the above characteristics, however it is known only as a single unit, and only used as a single sieve, not multiple sieves.